The purpose of this research is to attempt to bring insight into the mechanism of hydroxylation of substrates by enzymes which have a significant function in neurochemical processes. Such biological reactions as hydroxylation of phenylalanine and tryptophan and nonspecific hydroxylation of drugs are of primary interest. The approach is to attempt to devise chemical models, based on biochemical mechanisms, and thus probe in further detail the molecular basis for these hydroxylation reactions.